Notice: We request that you don't just set up a new account at this time if you are a previous user.
If you used to be one of our moderators, please feel free to reach out to Chris via the facebook Outerlimits4x4 group and he will get you set back up with access should he need you.
Recovery:If you cannot access your old email address and don't remember your password, please click here to log a change of email address so you can do a password reset.

Trailer Draw bar length

General Tech Talk

Moderators: toaddog, TWISTY, V8Patrol, Moderators

Post Reply
Posts: 12
Joined: Thu Mar 02, 2006 8:15 pm

Trailer Draw bar length

Post by jlmac »

Hi Guys

I want to increase the draw bar length on my trailer.
1.8 meters seems to be what quite a few people are using.
My question is, where is the length measured from. 1) The spring hanger to the coupling or 2) the front of the tray to the coupling?

Cheers
Justin
1996 KZN185
Posts: 4825
Joined: Sun May 04, 2003 6:33 pm
Location: Berwick vic

Post by droopypete »

The dimension is irrelevant, it is a question of balance,
single, double or triple axle?, where the weight is positioned?, there are heaps of factors that need to be considered or it will be a pig.
Peter.
Cable bracing is the way of the future!

v840 said "That sounds like a booty fab, hack job piece of shit no offence."
Posts: 12
Joined: Thu Mar 02, 2006 8:15 pm

Post by jlmac »

More information.

Trailer is a 6x4 unit with a fold out canvas tent on top(the same as most camping trailers). Single axle.
Only new additions will be a 65L water tank which will go underneath at the back, a large style tool box on the draw bar and the spare tyre also on the draw bar.
The trailer has no kitchen or anything fancy at all, weight positioning will be determined by how well I pack the trailer :)

Cheers
Justin
1996 KZN185
Posts: 179
Joined: Mon Feb 06, 2006 3:51 pm

Post by Spimon_NH »

*edit*
Whoops. I completely missed your question. No, I have no idea. Maybe go
check out a trailer shop with ur tape measure :?
Posts: 436
Joined: Sun Jun 13, 2004 3:02 pm
Location: Building true offroad trailers and campers

Post by dieseldude »

The 7 x 4 box camper trailer which I'm currently making has a drawbar length of 1900mm from the front edge of the box.

As said before - it depends on how it is going to be balanced. With my set up (where the axle is positioned under the trailer), I have a drawbar weight which I can lift myself - but it's still heavy enough to stop the rear of the vehicle bouncing.....

I reckon a length of around 1800mm on a 6 x 4 camper would be fine though...

Anthony
Droughtmaster Offroad Trailers and Campers

Offroad Camper MkI - Build up:
http://www.outerlimits4x4.com/phpBB2/viewtopic.php?t=106712
Posts: 522
Joined: Sat Jan 29, 2005 7:40 am
Location: Melbourne, Vic

Post by Toy80Diesel »

You need to have at least 10% ball-weight for the trailer to tow properly. If you increase the drawbar length, this decreases ball-weight. Then what you add onto the drawbar will obviously increase it again. If the ball-weight is too light (under 10%) it will cause the rear of the vehicle to bounce everytime the trailer wheels hit a bump in the road.
Shut Up, Get Out, & Start Digging...
Posts: 292
Joined: Sat Apr 29, 2006 2:32 pm
Location: New Zealand

Post by David_S »

And don't forget that the longer the drawbar the easier it is to reverse.

And I would measure its length from the ball to the axle, the axle being the fulcrum about which the unit pivots when you lift the ball.
1982 Patrol K160 SWB (MQ) 4L P40 Petrol with Megasquirt fuel injection and EDIS ignition. Warn 8274 winch with Gigglepin head
Posts: 4825
Joined: Sun May 04, 2003 6:33 pm
Location: Berwick vic

Post by droopypete »

David_S wrote:And don't forget that the longer the drawbar the easier it is to reverse.

And I would measure its length from the ball to the axle, the axle being the fulcrum about which the unit pivots when you lift the ball.
Give this man a cigar :)
Cable bracing is the way of the future!

v840 said "That sounds like a booty fab, hack job piece of shit no offence."
Posts: 4825
Joined: Sun May 04, 2003 6:33 pm
Location: Berwick vic

Post by droopypete »

jlmac wrote:More information.

Trailer is a 6x4 unit with a fold out canvas tent on top(the same as most camping trailers). Single axle.
Only new additions will be a 65L water tank which will go underneath at the back, a large style tool box on the draw bar and the spare tyre also on the draw bar.
The trailer has no kitchen or anything fancy at all, weight positioning will be determined by how well I pack the trailer :)

Cheers
I don't completely understand the purpose of your thread, if you have a trailer you are happy with, leave it alone. if you want it longer, lengthen it, where you measure it from makes no difference.

I have 3 6'x4' trailers with draw bars ranging from about 2m to 3.5m and loaded properly they all tow great (the long one is my fav)

My only advice is to make it as long as possible, you can back mine at speed with confidence and carry loads up to 5m long.
Good luck.
Peter.
Cable bracing is the way of the future!

v840 said "That sounds like a booty fab, hack job piece of shit no offence."
Posts: 12
Joined: Thu Mar 02, 2006 8:15 pm

Post by jlmac »

Peter, The reason for lenghting the draw bar is to make it tow/reverse better. I have heard quite a few people use 1.8m draw bars and I was not quite sure where the measurement was taken from, hence my first question.
Now than I have a better understanding off how it all works I will make the draw bars 2.45m long as measured from the spring hangers. This will make it 1.8m long from the front of the tray.

Cheers
Justin
1996 KZN185
Posts: 5256
Joined: Fri Jun 16, 2006 6:49 pm
Location: Melbourne

Post by Struth »

A good rule of thumb is to ensure that between 10% to 20% of the trailers loaded mass is placed on the tow bar, 15% being the ideal.

This can be acheived best by positioning the axles but is pretty hard to do on a completed trailer.

The longer the drawbar the less the trailer will react to steering when being reversed, the opposite applies for a shorter draw bar.

Cheers
Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests